860 FLIGHT International, 3 june (96i :
AIR TRANSPORT
BOEING 707-820
First details of the longer, faster, heavier and more
powerful new 279-seat Boeing
FOR some years speculation has been rife about the possibilities
of stretching the subsonic long-haulers—the 707, DC-8 and VC10.
Now, at last, two of the solutions are known. Douglas publicly
showed their hand six weeks ago with the DC-8-61 series, for
which actual airline orders have been placed (by Eastern and
United). Now Flight is able to reveal the first published details of
the Boeing 707-820, which is being offered in two gigantic versions—
the 260-passenger 505, and the 279-passenger 506.
While engineers may shudder a little at the flexural problems of
200ft aluminium tubes, accountants are going to like the shape of
these aeroplanes. But the stake is considerable—an airline has got
to be pretty big to consider taking on such monsters.
With a good flow of orders coming in for 7O7-32OBs and Cs and
727s, and with a big programme ahead on the short-haul 737,
Boeing have not forced the pace with the -820. As yet no Boeing
decision has been announced, nor has any statement been made on
the minimum number of orders necessary before going ahead. But
it may be guessed that Pan American, TWA and American have
advised Boeing of their likely requirements, and one more could set
the ball rolling.
BOAC say they have not approached Boeing about possible
820 deliveries, although Boeing have approached them in the
course of normal sales liaison. BOAC say they have not reserved
any delivery positions on the 820, though naturally they are keep-
ing in close touch with Boeing as well as with BAC and Douglas.
The two 707-820 versions are the 505 with a 45ft longer fuselage
than the 707-320B, and the 55ft longer 506. Both are powered by
22,5001b thrust Pratt & Whitney JT3D-15 turbofans and have the
same bigger wing area, by root extensions which add nearly 10ft
to the span.
Operating cost estimates are notoriously suspect, especially
when they come from manufacturers. But Boeing are hardly
Powerplant
Sea level thrust (1b)
Dimensions (decimals)
Span (ft)
Length (ft)
Height (ft)
Accommodation
Mixed-class seating
All-economy seating
Under-floor volume (cu ft)
Fuel tankage (US gal)
Weights (Ib)
Taxi
Zero-flaps
Zero-fuel
Landing
Operating weight empty
Price (% million)
Engine price
707-320B
JT3D-3B
18,000
145.8
152.9
42.5
135
187
1,770
24,855
336,000
331,600
195.000
215,000
143,000
7.25
0.26
707-820(505) 707-820(504)
JT3D-I5
22,500
155.5
198.6
48.1
209
260
3,000
30,600
412,000
408,000
265,000
290.000
184,600
10.17
0.335
155.5
208.6
48.1
225
279
3,400
30.600
412,000
408,000
270,000
295,000
188.400
10.42
0.335
likely to knock their own 320B, about which they know something.
From every economic viewpoint the -820s promise great things for
the really busy long-haul routes. According to version and length,
estimated seat-mile costs are 13 to 26 per cent less than those of the
-32OB; and for a given revenue rate and load factor, profit is
handsomely increased. Aircraft-mile costs of the -820 are naturally
higher (21-23 per cent) and 12-15 more passengers are needed to
break even (break even load factors are lower).
i To get back for a moment to fundamentals, the whole point of
cramming an enormous number of people into one thin aluminium
tube is to cut costs. Such mass travel in one aircraft is unlikely
to be a selling point, but as more and more of the smaller, high-load-
BOAC are an obvious target, after PAA, TWA and American, for Boeing 707-820 salesmen